SU 4x4 Midi working on PC but only partly on OSX 10.13

I am using a US-4x4 interface on both, a PC (Windows 7) and a Mac (OSX 10.13 High Sierra). On both, I am using Ableton live with a plugin called "Circular Labs Mobius". Audio works fine on both environments. Midi works great on the PC, but not on the Mac - there, the plugin misinterprets some of the commands send from a midi foot controller (and other controllers as well, I checked that).

I am sure, that the software is configured correctly on the Mac: When controlling the software from a USB-Keyboard (M-Audio O2), everything works like it should.

Tricky, uh? Any hints are highly welcome. US4x4 is on latest patch-level (done via the PC, if that matters). Already removed the interface/drivers (Audio-Midi-Setup) and reconnected the device.

Solved the problem myself: The plugin received midi straigth from the interface as well as through the host DAW (Ableton). Strange enough, this only happens on the mac, so midi routing seems to be somehow different on OSX. Switching on of the two paths off solved the problem.